Known shaving foils are usually equipped with a periodically recurring aperture pattern in which the aperture cross-sections have a hexagonal, honeycomb-shaped geometry, a slot-shaped and/or circular geometry, or polygonal geometry—in particular equilateral polygonal geometry. Complete parqueting of the foil surface is easy to accomplish with honeycomb-shaped apertures. At the same time, foils having honeycombed-shaped apertures can include a very favorable ratio of bar area (e.g., solid area around the aperture) to aperture area. Foils with a honeycomb-shaped aperture structure have proven successful in practice for many years and enable a particularly thorough shave, while at the same time are extremely gentle on the skin.
When designing aperture patterns for shaving foils it is always necessary to optimize the compromise between thoroughness, for which particularly large aperture dimensions are suitable, and gentle treatment of the skin, which can be improved by smaller aperture dimensions. For example, in a more expansive shaving foil aperture, the skin can be pressed partially closer to the undercutter as the undercutter moves relative to the shaving foil. As a result, thoroughness is improved because the undercutter can be moved closer toward the hair root. However, at the same time, there is a higher risk, of course, that the user's skin will be irritated or at worst injured because the user's skin is also moved closer to the undercutter.
Regularly arranged aperture patterns result in very little variation in the alignment of the bars between the apertures. Bar alignment plays a particularly great role in the actual process of threading in and cutting hair. Generally, in foils having honeycombed-shaped apertures and/or foils described in accordance with DE-A 1 553 668, there are three to four preferred directions of parallel running bars in relation to the blades of the moving undercutter. Hair growth on the human skin, particularly growth of beard hair, is highly irregular by comparison, not only with regard to the distribution of individual hairs on the skin surface but also in terms of the spatial alignment of individual hairs in relation to each other. Hence, the more alignments provided by the bars of a shaving foil, the greater the probability of a cutting action taking place between a bar and a blade of an undercutter.
Shaving foils can also include several perforate regions, each with a different aperture geometry as shown in DE-A 1 553 668. However, the aperture patterns of the individual perforate regions shown in DE-A 1 553 668 are themselves periodic, and thus limit the probability of a cutting action taking place.